Vehicle spring



Patented Jan. 11, 1927.

UNITED STATES `1,613,700 PATENT oFFicE.

ALBERT Gr. GEISTERT, OF DETROIT, MICHIGAN, ASSIGNOR TO GENERAL MOTORS COR- PORATION, OF DETROIT, MICHIGAN, A CORPORATION OF DELAWARE.

VEHICLE SPRING.

Application filed November 24,A 1923. Serial N100. 676,759. i

The invention relates to vehicle springs, and more particularly to those of the type including a plurality of superposed leaves of graduated lengths, the larger end of the spiiiig constituted by such assembled leaves being secured lixedly to the vehicle frame, as by a suitable bracket, and the smaller end being connected to the vehicle axle.

The invention is of especial utility in connection with, and will herein be specifically described as embodied in, the front spi'ings of an automobile, this type of spring being adapted for and now employedin relatively light cars.

The more distinguishing featuresl of the invention ielate to the shape of the springer its leaves, and to its support or attachment to the vehicle chassis and axle. VrThe individual leaves of the spring are cambered to an initial curvature substantially in the arc of a circle, from which characteristic the spring may be designed a' true-arcv spring. rThe spring is mounted with the loiigei' leaves at the lower side and with the curvature downward, so that deflection under load will merely add to the degree of initial curvature. Various advantages of this speciiic form and arrangement of spring are hereinafter pointed out, as well as of the meansA I have devised for the securing of the spring to the body orchassis to be supported. A

in the accompanying drawings, Figure 1 is side elevation of a part of a motor ve'- :i hicle chassis having associated therewith an embodiment of my invention.

Figure 2 is a plan view of the structure shown in Figure 1.

Figure 3 is a section on line 3 3 of Figure 2. f Figure t is a section on line 4 1 of Figure 2, and Figure 5 is avdiagrammatic view illustrating the operation of the spring.

Referring to the drawings, 10 indicates a side member of a motor vehicle chassis frame7 which member is shown as of channel form with the open side of the channel inward. A cross member 11 joins the member 10 to a similar side memberV on the other side of the vehicle, a bumper 12 being secured to the lower side of the cross member.

A front axle 13, preferably of I-beainl form, provided with an enlarged portion 1/1 serving as a spring pad or seat, carries at its outer end the arms 15, 16, between which is mounted the steering knuckle 17 supported on king pin 18 and positioned by steering arm 19. rlhe parts justv described are of usual and well known construct-loir and may, of course, be varied as desired.

The spring'indicated byf20, which spring will, of course, be duplicated upon the opposite side of the vehicle, comprises the longerleaves 21, 22, and a number ofleaves of graduated lengths, the number depending upon the strength ofindividual leaves and Jthe character of service required, the shortest leaf being indicated by 2B. The llower leaf 21 is fixed 'at its forward end to the axle 13 by bolt 24 passing through Vboth flanges ofthe axle. A collar 25 surrounding the bolt 241 and positioned 'beneath the head thereof serves to clamp the leaf 21 to the spring seat. The leaf 22 is provided with an elongated aperture'26-within which the collar 25 is positioned, thus permitting relative longitudinal movements of .the two leaves, as required by varying deflection of the spring, and at the same time preventing separation of the leaf 22 from. the axle' An ad-4 should leaf 21 be broken in service. ditional clamping means maybe provided comprising` the U-bolt 27, which also pre- 'vents lateral play of the leaves while per initting relative longitudinal 'movements The larger or butt end of the spring 20 is secured to the frainevii'ieinbei' 10 by a bracket 30 which is fixed to the member 10 as by Vrivets 31. The bracket is formed with a seat portion 32 to receive the spring 2t), and also with a rear flange or projection 83 adapted to receive and be secured to a transverse frame member 34, preferably of channel vform. The spring 2O is clamped to the bracket by a U-bolt 85 fitting over a.

saddlelpiece 36 which rests uponleaf 23.V

U-bolt extends through apertures in the spring seat! portion of the bracket and is firmly secured as 'by nuts 37. A single bolt or the leaves thereof, and has been found of marked utility in eliminating wear and shearing of the securing bolts.` i

It will be understood that the spring bracket for the vopposite side of the vehicle will not be identical with that shown, but that thev two will be related as rights and lefts While I have referred to the spring leaves as being of uniform curvature throughout, and this will be preferable for the longer leaves, it will be understood thaty a shorter: leaf, such as the leaf 23, need not necessarily be curved since its function is chiefly to apply resistance to abnormal deflection of the longer leaves, and it may, in fact, withy advantage be made from fiat stock.

In the diagrammatic illustration in Figure 5, I have shown at c the position of the spring when not under load, at CZ the position under approximately normal load, and at c the bumper position, or position of ez;- treme deection.

For ease in steering it is considered desirable to give the king pin axis a slight rake or rearward inclination, this inclination being indicated in the drawings, Figure l, as amounting to from 2 to 4, the line o indicating the vertical and the line b the king pin axis. For convenience in manufacture of the front axle, however,vit is best to form the spring seat in a plane perpendicular tothe central vertical plane of the axle. This necessitates the positioning of the frontend of the' spring, as the leaves 2l, 22, ata slight downward inclination rearwardly. lith my improved spring this position is provided for, and at the same time the curvature is sufficient to bring the rear end of the spring to a position immediately adjacent to the side member of the frame and in, the horizontal plane thereof, thus simplifying the form of the bracket required at that point, saving a considerable excess of material that would be required if'the bracket were dropped to the position necessary if the spring were not curved, and greatly improving the sturdiness of the connection It will be understood that the operation of the improved spring will be smoother and more uniform under varying loads than is possible with a spring of S-shape, such as has commonly been employed hitherto in this art, or of other non-uniform curvature. |Ihis is due to the fact that the leaves r main incontact throughout their length both in the initial and all subsequent positions,

the curvature remaining substantially uniform ina the contacting areas ofy successive leaves whatever the deflection. Furthermore it will be noted that, by reason of the upward,curvature of the front endV ofthe spring, the direction ofiroadgshocks transmitted through the axle is more' nearly transverse to the spring than would be otherwise4 obtainable, thus contributing to easy riding qualities, relieving the spring, and reducing materiallythe endwise thrust on the spring bracket and 4securing means.Av

Thev spring describe-d has particular advantages also in the reduction of cost of manufacture. Since the curvature is the same throughout the length and is identical in the successive cainbered leaves, the desired camber is obtainedsimply by rolling the stockto a constant degree of curvature without special machinery or manipulation.

lhile I havey describedl herein specific details of construction, I doy not desire to be restricted thereby, but wish to include all variations falling within the scope of the invention as dened in the appended claims.

I claim: K l. A vehicle. spring comprising a plurality of superposed leaves of graduated lengths, one end of each leaf being secured tothe vehicleV frame and the other end ofja long leaf being secured lrigidly to the axle, the long leaf and several superpose-d leaves having Vinitial uniform downward curvature in the arc of a circle.

2. In vehicle springconstruction, a. frame member, al front axle'having a spring seat with a downward inclination rearwardly, a leaf spring secured at its forward end Vto ,said seat and curved upwardly in the arc of a circle. from the axle, and means for'securiingY the rear end of said spring vfixedly to the frame member.

3. In a vehicle spring construction, a vehicle side frame member, a spring comprising a plurality of superposed leaves of gradA uated lengths, the rear end of each leaf being fixed to said member in substantially the horizontal plane thereof, said spring extending downwardly and fori-var lly with an initial downward camber in a circular arc'in the leaves thereof, a longer leaf having normally an upward'direction at its forward end, a front axle, and means Vfor securing said forward end to said axle.

In testimony whereof I aflix my signature.

ALBERT e. enrsrnn'l.A

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